<template>
    <div>
        <input v-model="v" type="text">
        {{v}}
        <button @click="changeData">换数据</button>
    </div>
</template>

<script>
export default {
    data () {
        return {
            v: '123',
        };
    },
    methods: {
        changeData () {
            this.v = Math.random();
        },
    },
};
</script>